691267919 has 2 divisors, whose sum is σ = 691267920. Its totient is φ = 691267918.

The previous prime is 691267903. The next prime is 691267931. The reversal of 691267919 is 919762196.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 691267919 - 2⁴ = 691267903 is a prime.

It is a super-2 number, since 2×691267919² = 955702671677181122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (691267949) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345633959 + 345633960.

It is an arithmetic number, because the mean of its divisors is an integer number (345633960).

Almost surely, 2^691267919 is an apocalyptic number.

691267919 is a deficient number, since it is larger than the sum of its proper divisors (1).

691267919 is an equidigital number, since it uses as much as digits as its factorization.

691267919 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 367416, while the sum is 50.

The square root of 691267919 is about 26291.9744218649. The cubic root of 691267919 is about 884.1965188797.

The spelling of 691267919 in words is "six hundred ninety-one million, two hundred sixty-seven thousand, nine hundred nineteen".